1. Field
Embodiments of the present invention relate to electronic circuits and, in particular, to delay-locked loops or any circuit incorporating phase tracking.
2. Discussion of Related Art
Delay-locked loops may be used for frequency synthesis, windowing techniques in communication interfaces, and/or other clocking applications. Traditional delay-locked loops have limitations however.
One limitation is that the tracking bandwidth, which is proportional to the loop gain, is also proportional to jitter peaking. Loop filtering is typically employed to reduce tracking bandwidth, but loop filtering merely reduces jitter peaking. Thus both poor tracking bandwidth and poor jitter response compromise the overall phase tracking.
Other limitations include longer tracking distance, which leads to increased static phase error, and low closed-loop bandwidth, which leaves a vulnerability to noise-induced jitter, or jitter accumulation, as well as other high frequency effects.